Title or type of protection - not the proper name. An official national predicate or grade, the formal title or type of protection (see level-table). Established as an additional key with the boundary=protected_area tag to help differentiate between similar areas within a class. Example values are: wildlife sanctuary, Zapovedniki, Nationalpark, Special Protected Area, World Heritage Convention, Aesthetic Forest, Heritage River, Indian Reserve, National Park, State Park, State Forest, National Forest, and Wildlife Management Area.